Unilateral biportal endoscopic thoracic costotransversectomy approach: a minimally invasive technique for thoracic...

Unilateral biportal endoscopic (UBE) surgery has advanced minimally invasive spine surgery, but existing techniques for thoracic disc herniation (TDH) face challenges when addressing calcified/sequestered discs and spinal stability. UBE with thoracic costotransversectomy (UBE-TCT) is a novel approach designed to preserve posterior bony architecture while allowing precise ventral decompression.

The primary aim of this study was to describe the detailed standardized surgical technique of UBE-TCT, and to preliminarily verify its anatomical feasibility, surgical safety, and short-term clinical outcomes in the treatment of TDH, as a technical feasibility report.

A retrospective analysis was performed on 6 patients with TDH who underwent UBE-TCT between March 2023 and September 2024. Three-dimensional computed tomography (3D-CT) was obtained to measure the Lateral Skin Entry Distance (LSED), thereby evaluating the anatomical feasibility of the UBE-TCT approach. Magnetic resonance imaging (MRI) scans were examined to measure the cross-sectional area of the thoracic spinal canal (CSA-TSC) and to assess the extent of decompression at the herniated disc site. Clinical outcomes were assessed using Visual Analogue Scale (VAS) scores for back and leg pain, and the Oswestry Disability Index (ODI) for thoracic-related disability.

A total of 6 patients (mean age 59.67 ± 8.78 years) involving 7 herniated thoracic disc levels were included in this study. The mean follow-up period was 17.83 ± 5.71 months. No conversion to open surgery or perioperative complications occurred. The average operative time was 120.83 ± 29.94 min, and the average postoperative hospital stay was 4.50 ± 1.38 days. The preoperative LSED, measured across all treated levels, was 36.07 ± 3.66 mm. Postoperatively, the CSA-TSC increased significantly from 135.48 ± 57.47 mm² to 174.93 ± 48.82 mm² (P < 0.05). Regarding clinical outcomes, significant alleviation of pain and functional improvement were observed immediately after surgery and maintained throughout the follow-up period (P < 0.01). Back VAS scores decreased rapidly from 7.50 ± 0.84 preoperatively to 3.17 ± 0.75 at 48 h postoperatively, further to 1.50 ± 0.84 at the last follow-up. Similarly, Leg VAS scores dropped from 6.17 ± 0.98 to 2.83 ± 0.75 at 48 h, and finally to 1.33 ± 0.52. The ODI also showed a progressive decline, improving from a preoperative baseline of 59.67 ± 9.07% to 44.00 ± 8.20% at 48 h, and reaching 15.33 ± 3.72% at the final assessment. According to the modified MacNab criteria, the excellent/good rate was 100% (5 excellent, 1 good).

This preliminary technical feasibility report suggests that UBE-TCT, as a minimally invasive endoscopic technique, is a preliminarily safe and anatomically feasible strategy for the treatment of ventral thoracic spinal canal stenosis caused by TDH.